Burner control apparatus



D 9 1941. B. E. sHAw 2,265,494

BURNER CONTROL APPARATUS original Filed Dec. i4, 1957 y :Nw-:2221, Nm) yfa@ ATTORNEYS Patented Dec. 9, 1941 BURNER CONTROL APPARATUS Burton E. Shaw, Bristol, Ind., assignor to Penn Electric Switch Co., Goshen, Ind., a corporation of Iowa.

Original application De 179,707. Divided an 1939, Serial No. 271,123

2 Claims.

An object of my invention is to provide burner control apparatus involving particularly a relay mechanism of simple construction, the present application being a division of my copending application, Serial No. 179,707, iiled December 14, 1937 now Patent No. 2,162,126,

Still a further object is to provide a relay in which a mounting member for the movable contacts is secured to the relay armature by a` single screw whereby the -mounting member may be readily removed from the armature and from the vicinity of a panel on which the relay is mounted for exposing both the movable contacts and thestationary contacts for inspection and cleaning purposes.

A further object is to provide a novel adjusting means for the movable contacts of the relay and for a spring pressure means provided for the y contacts.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my burner control apparatus whereby the objects contemplated are attained, as hereinafter more fully set forth,l pointed out in my claims and illustrated in the accompanying drawing, in which:

Figure 1 is a front elevation of a control apparatus embodying my invention and showing the cover therefor removed;

Figure 2 is an enlarged sectional view on the line 2 2 of Figure 1 showing the relay of the control apparatus in de-energized position;

Figure 3 is an enlarged sectional view on the line 3 3 of Figure 1 showing the contacts of the relay in closed position;

Figure 4 is a sectional view on the line 4 4 of Figure 3, and- Figure 5 is a sectional view similar to Figure 3 showing the relay contacts open.

vOn the accompanying drawing, I have used the reference numeral I0 to indicate a housing of a control apparatus. This apparatus is usually called a stack switch. Within the housing I 0, a panel I2 oi insulation or the like is mounted. A safety switch SS and a combustion switch CS are mounted on the panel IIJ but the details of these two switches form no part of my present invention. Details of the combustion switch CS may be found in my oopending application Serial No. 179,708, led December 14, 1937.

In connection with my burner control apparatus I provide a relay including a relay coil RC. A core I3 is provided for the relay and the core is suitably supported in a framework which 55 is cember 14, 1937, Serial No. this application May 1,

(Cl. 20G-'165) includes perforated ears I 4 pivoted on a pin I5. On the ears vI4 is an L-shaped armature I6. A spring I'I normally retains the armature in the position of Figure 2 with an extension I8 of the armature engaging the core I3 to act as a stop in one direction. A stop I8a acts in the opposite direction to limit movement of a mounting member MM. y

The mounting member MM is secured to the armature i 6 by a single screw I9. The mounting member has a pair of side iianges 20 which engage the sides of the armature I6 to prevent undesired rotation of the mounting member relative to the screw I9. The mounting member MM ispreferably formed of insulating material and has a pair of threaded bores 2|. Within each bore 2| a sleeve 22 is mounted and these sleeves are slotted as indicated at 23 so that a forked screw driver may be utilized for adjusting them axially of the bores 2l.

Each sleeve 22 has threaded in it a headed element or screw 24. A contact carrier 26 is slidably mounted on each headed element 24 and rotation thereof is prevented by an L-shaped extension 26a mounted loosely in a slot 2l of the mounting member MM. Springs 28 are interposed between the contact carriers 26 and the sleeve 22.

One of the contact carriers has a pair of movable contacts 29 mounted thereon for cooperation with stationary contacts 30. The contacts 29 and 30 constitute a motor switch MS. The other contact carrier has similar movable contacts 29a cooperable with similar stationary contacts 30a (seeFigure 8). The contacts 29a and 30a constitute a holding switch HS. An ignition switch IS is provided comprising a bracket 3I carrying a stationary contact 32 and a bracket 33 supporting a movable contact 35. The contact 34 is mounted on a leaf spring 35 which in turn is riveted as at 36 to the bracket 32.

In connection with the ignition switch IS I provide an ignition trip coil ITC. The coil ITC may be an electromagnet and may be suitably mounted on the core I3 of the relay by a bracket 31. Pivoted on a pin 38 carried by the bracket 3l is an armature 39 adapted to be attracted by energization of the ignition trip coil ITC. The armature 39 carries a cross piece 40 of insulation adapted to contact with the spring 35 and thereby lift the ignition switch contact 34 oi the Contact 32 when the ignition trip coil is energized.

An ignition trip switch ITS is provided which similar to the ignition switch IS and therefore it is not shown in detail although the leaf spring and contacts thereof are shown in Figure l at 35d, 32a and 34a.

A latch lL is provided for the armature 39 in the form oi a leaf spring carried by the armature. The latch L is normally in the lposition of Figure 2 with its lower end resting on an abutment bracket A. The mounting member MM has a socket 4i in which there is a. latch release The latch release consists of an L-shaped strip of metal located in the socket and constrained to ther position in Figure 2 by a spring 42 interposed between the short arm of the latch release and a plate d3.

Practical operation Brieiiy, attraction of the armature I6 by energization of the relay coil moves the armature and its attached parts from the position of Figure 2 to position against the stop Isa, thus closing the contacts 29 and 29a against the contacts 3B and 36a.

The mounting member MM being mounted on the armature it so that it can be conveniently removed therefrom by the simple expedient of removing the single screw I9, makes it possible to remove the movable contacts 29 and 29a of the motor and holding switches so that they can be readily inspected and cleaned. Removal of these contacts from the vicinity of the panel i2 also exposes the stationary contacts 30 and 30a so that they can likewise be inspected and cleaned.

The particular mounting of the movable contact relative to the mounting member and thereby the armature I6 as shown in Figures 3 and 4 permits a double adjustment that takes care of manufacturing tolerances as voltage of the relay. The sleeve 22 being threaded in the bore 2i and the screw 24 being threaded in the sleeve 22 permits both adjustment of the head 24 relative to the armature I6 and adjustment of the tension of the spring 28. The screw 24 can be adjusted so that the ilnal position of its head as determined by the armature I6 engaging the stop I8a of the relay is either close to or relatively far away from the contact carrier 26. Accordingly the desired distance of travel of the armature toward open switch position may be adjusted sothat the pickup of the contact carrier occurs after the desired travel. of the armature from closed switch towell as the drop out ward open switch position. The tension of the spring 28 may be increased or decreased asde sired. An increase thereof results in the spring exerting greater pressure to open the relay switch and thereby causes the relay to operate at a higher drop out voltage. Similarly a decrease in the spring tension will cause opening of the relay at a lower drop out voltage.

The foregoing adjustments of the sleeve 22 and tion and arrangementof the parts of my burner control apparatus without, however, departing from the real spirit and purpose thereof. It is accordinglymy intention to cover by my claims any modied forms of structure or use of mechanical equivalents which may be reasonably included Within their scope.

i claim as my invention:

l. In apparatus of the class described, a. stationary contact, a movable mounting member, a

headed element carried by said mounting membera contact carrier slidable thereon, a movable contact carried by said contact carrier and cooperable with said stationary contact when said mounting member is moved toward said stationary contact, `a sleeve threaded in said mounting member, said sleeve being located between opposite surfaces thereof, said headed element being threadedly mounted in said mounting member with its headed end projecting from one surface thereof and its other end ccuntersunk below the other surface thereof, and a spring on said headed element interposed between said contact carrer and said sleeve whereby the degree of tension of the spring may be varied'by rotating the sleeve relative to said mounting member and the distance of the head of said headed element from said mounting member may be varied by rotating the headed element relative to said sleeve.

2. 'In 'apparatus of the class described, a stationary contact, a movable mounting member having a bore extending therethrough, a sleeve of less length than, and threaded in said bore, a headed element threaded in said sleeve and extending from said mounting member, a contact gree of tension of the spring may be varied by relatively rotating the sleeve and mounting member, and the distance of the head of the headed element from said mounting member may be varied by relatively rotating the headed element and the sleeve.

BURTON E. SHAW. 

